The Chemical Structure of the Heavy Chains of Human Immunoglobulin G

Abstract

There is evidence that the antibody activity of immunoglobulins is related to their primary sequence (Whitney and Tanford, 1965a, b; Haber, 1964), but this can only be proved by determination of the amino acid sequence of several pure antibodies. Attempts to determine the amino acid sequence of the constituent heavy and light chains of antibodies are complicated by the heterogeneity of all antibody preparations, much of the heterogeneity being unrelated to antibody activity. Myeloma proteins, including Bence-Jones proteins, are, however, relatively homogeneous and, if the assumption is made that these pathological immunoglobulins are constituents of normal immunoglobulins, then it is legitimate to draw conclusions about the structure of normal immunoglobulins and antibodies from chemical studies of pathological proteins.